New York: PSA Rising, February 2, 2002. A clinical trial of an herbal product previously shown to shrink some prostate cancers has been halted after tests found traces of synthetic estrogen mixed in with the herbs.

Dr. Eric Small, an oncologist at University of Californa San Francisco reported two years ago that BotanicLab's PC SPES lowered PSA and shrank tumors in men with advanced prostate cancer. This year Dr. Small and Dr. William Oh at Dana Farber planned to enroll a hundred patients in a randomized trial to compare PC SPES with Diethylstilbestrol (DES), an artificial estrogen. As this trial began to accrue, the doctors saw that men who received PC SPES actually did better than men receiving DES (although not quite as well as patients taking PC SPES in the earlier study).

But last month both doctors halted the trial. They told patients that the PC SPES, supplied directly from the manufacturer, had itself tested positive for DES.

This did not come out of the blue. Two laboratory reports commissioned last fall by prostate cancer patients detected levels of DES in some lots of PC SPES. Certain other lots that seemed ineffective showed no signs of DES.

According to BotanicLab, the Food and Drug Administration tested the product last summer and found no traces at all of DES or any other artificial estrogen.

Dr. Robert DiPaolo and Dr. Michael Gallo at Rutgers University, NJ reported in the New England Journal of Medicine in 1998 that PC SPES contained phyto (plant) estrogen. "We actually looked for [DES]," Dr. Gallo said last fall. They ran tests on the PC SPES after Dr. Paolo noticed that patients who were taking the herbs had breast enlargement, loss of potency and sexual desire and other signs of estrogeneity. "We looked very hard." Dr. Gallo said, "and never saw a DES peak or estradiol peak." "I would be extremely disheartened if in fact those guys were lacing it," Gallo said.

"Although initial reports published in 1998 and a subsequent study undertaken by the FDA (Food and Drug Administration) indicated that there was no DES present in the PC SPES lots studied," Dr. Small said in a letter January 4, 2001 to his enrolled patients, "recent reports have suggested that some lots of PC SPES might contain DES."

"Because of ongoing concerns about the contents of PC SPES," Small said, "we have recently decided to test each of the lots provided to us for the study by BotanicLab. We tested samples from all 4 lots used in the study. The laboratory tests revealed that each of the lots tested had small amounts of DES present. The DES found in each of the PC SPES lots was 1/30th (3%) or less of the amount given to patients receiving DES pills."

Patients in the DES arm of the trial received 3 mg of DES per day.

All the batches came directly from BotanicLab in Brea, CA, a private company founded by patent-holder Sophie Chen, Ph.D. and associates.

PC SPES Group Got Better Results

Patients enrolled in the PC SPES arm of the trial before it was halted were showing better responses than those receiving DES. Of the PC SPES group, 45% had at least a 50% drop in PSA (prostate specific antigen, a biochemical marker of prostate cancer). Only 21% of those on DES experienced a 50% drop. All of the patients had androgen independent prostate cancer; none of them had received chemotherapy or other advanced therapy.